1. Field of the Invention
The present invention relates to processing methods of holes using a complete die that includes a pair of a punch and a die, and a plate holding the same. The invention more particularly relates to a processing method suitable for processing a shouldered hole, in which an orifice of a fuel injection valve is formed, inclined relative to an axis of the fuel injection valve, together with a recessed portion having a diameter larger than an orifice diameter at an outlet portion of the orifice.
2. Description of the Related Art
A known apparatus for processing an orifice includes a stage movable in an X-axis direction and a Y-axis direction and an elevator mechanism movable vertically in a Z-axis direction. The apparatus further includes a rotational mechanism disposed on the stage, the rotational mechanism being oscillatable about an axis extending in parallel with a stage surface and rotatable about an axis extending perpendicularly to the stage surface. A collet chuck holding an orifice plate as a workpiece is fixed on the rotational mechanism and a tool holder holding a processing tool is fixed on the elevator mechanism (see JP-2008-184977-A). This processing apparatus includes a tool changer that exchanges processing tools, capable of processing a plurality of recessed portions and orifices, each of the recessed portions and orifices having a unique diameter different from each other, by exchanging processing tools with the orifice plate as the workpiece held in the collet chuck. In addition, the orifice plate held in the collet chuck is moved in the X-axis direction and the Y-axis direction by the stage and angled at varying inclination angles relative to the processing tool by the rotational mechanism, so that six sets of recessed portions and orifices are processed having an axis of each of the recessed portions and orifices inclined at a unique inclination angle relative to a central axis of the orifice plate.